New satellite analyses reveal two decades of glacier retreat in Greenland
Greenland glaciers have lost vast areas of ice in the past 19 years. This is despite a recent period of growth at some locations.
Satellite photos track the front line positions of Jacobshavn Isbræ on the west coast of Greenland. The 2018 position is marked by the red line. (Illustration: Andersen et al. 2019)
Climate change is causing a group of glaciers in Greenland to lose more ice into the fjords than previously recorded. This might not sound particularly new, but it is the first time that glaciologists have put precise numbers to the area of ice lost in recent years. The results are published in a new scientific article in the peer-reviewed open access journal Geological Survey of Denmark and Greenland Bulletin.
Since 1999, a group of 47 glaciers has lost around 2100 km 2 of ice – an area roughly the size of Paris – says Robert Fausto, a senior research scientist in glaciology and climate at the Geological Survey of Denmark and Greenland (GEUS), Denmark.
“The fact that so much ice has disappeared doesn’t surprise me at all, because scientists have understood that for 20 years. I go to Greenland myself each year for fieldwork and I can see it happening,” says Fausto.
Fausto points out, however, that some of the 47 glaciers that he and his colleagues studied have actually advanced a little during this period. For example, Jakobshavn Isbræ on the west coast normally calves off the most ice each year, but in 2017 it actually advanced a little, after years of retreat. The front line of the glacier remained at approximately this same location in 2018. More ice lost but also some gained
“It’s quite clear that even though climate change tends to lead to more and more ice loss, there’s also variability from year to year,” he says.
This variability is often interpreted, mistakenly, as evidence that the effects of climate change are not so bad after all, says Fausto.
“The underlying physics of a warmer world fit perfectly with the advance of some glacier fronts in recent years, for example at Jakobshavn Isbræ. A warmer atmosphere generates more and more extreme weather around the average conditions that are constantly warming,” he says.
Fausto is keeping a close eye on the weather expected this summer in Greenland, which is usually a good indicator for how the glaciers might behave during the melt season. European weather a good indicator for Greenland ice loss
Warm summers in Northern Europe typically coincide with cold summers in Greenland, which would mean less ice loss that year. And a poor European summer typically occurs alongside warmer summer weather in Greenland, leading to more ice loss.
“It’s always exciting to see what happens over the summer. And if the weather is bad over here, you can always just sit inside and watch the glaciers,” says Fausto.